使用链表 C++ 的简单工资单系统

Question

我只是在创建一个工资单系统，该系统具有该员工的员工姓名和工作时间..数据应该存储在链表数据结构中，但我无法将链表连接到类员工的对象，我尝试将工资单链表(即empList(作为静态成员，以便类的所有对象都可以使用相同的列表对象并且可以存储数据，但是一旦我编译了代码，我就会在第 130 行收到"未定义的对 employee：：empList 的引用"的错误，这是构造函数的最后一行，在第 150 行上出现相同的错误，这是一个打印工资单函数。无论我在哪里尝试在员工类中调用任何 payRollLinkedList 类的函数，它都会出错。最重要的是，我想要的只是将数据存储在员工的双向链表中，而我无法访问该列表。

#include <iostream>
using namespace std;
class payRollLinkedList;
class node
{
private:
node* previousPointer;
string name;
int hoursWorked;
node* nextPointer;
friend class payRollLinkedList;
public:
explicit node(const string argName, const int argHoursWorked)
: previousPointer{nullptr}, name{argName}, hoursWorked{argHoursWorked}, nextPointer{nullptr}
{}
};
class payRollLinkedList
{
private:
node* headPointer{nullptr};
node* tailPointer{nullptr};
node* getNewNode(const string argName, const int argHoursWorked)
{
return new node(argName, argHoursWorked);
}
public:
void addAtBack(const string argName, const int argHoursWorked)
{
node* newNode{getNewNode(argName, argHoursWorked)};
if(isEmpty())
{
headPointer = tailPointer = *newNode;
}
else
{
tailPointer->nextPointer = newNode;
newNode->previousPointer = tailPointer;
tailPointer = newNode;
newNode = nullptr;
delete newNode;
}
}
bool deleteNode(string argName)
{
node* currentPointer{headPointer};
if(isEmpty())
{
cout <<"the list is already emptyn";
return false;
}
else
{
while(currentPointer != nullptr)
{
if(currentPointer->name == argName)
{
if(currentPointer == headPointer)
{
node* tempPointer{headPointer};
headPointer = headPointer->nextPointer;
tempPointer->nextPointer = nullptr;
headPointer->previousPointer = nullptr;
delete tempPointer;
break;
}
if(currentPointer == tailPointer)
{
node*tempPointer{tailPointer};
tailPointer = tailPointer->previousPointer;
tempPointer->previousPointer = nullptr;
tailPointer->nextPointer = nullptr;
delete tempPointer;
break;
}
node* tempPointer{currentPointer};
node* nextPtr{tempPointer->nextPointer};
currentPointer = currentPointer->previousPointer;
currentPointer->nextPointer = nextPtr;
nextPtr->previousPointer = currentPointer;
tempPointer->nextPointer = nullptr;
tempPointer->previousPointer = nullptr;
currentPointer = nullptr;
nextPtr = nullptr;
delete tempPointer;
delete currentPointer;
delete nextPtr;
}
else
currentPointer = currentPointer->nextPointer;
}
return true;
}
}
void print()
{
if(isEmpty())
{
cout <<"nothing to shown";
return;
}
else
{
node* currentPointer{headPointer};
while(currentPointer != nullptr)
{
cout <<currentPointer->name <<"t";
currentPointer = currentPointer->nextPointer;
}
}
}
bool isEmpty()
{
return headPointer == nullptr? true : false;
}
};
class employee
{
private:
string name;
int hoursWorked;
static payRollLinkedList empList;
public:
employee()
: name{""}, hoursWorked{0}
{}
employee(string argName, int argHoursWorked)
{
name = argName;
hoursWorked = argHoursWorked;
empList.addAtBack(name, hoursWorked);
}
void printPayRoll()
{
empList.print();
}
};
int main()
{
employee emp("usman", 12);
employee emp1("ali", 12);
emp.printPayRoll();
}

Answer 1

https://en.cppreference.com/w/cpp/language/static

您需要在全局范围(类外(定义类的静态成员。 我建议你拆分你的代码.h和.cpp文件，并在.cpp文件中定义成员。

payRollLinkedList employee::empList;